Informed consent for suspension microlaryngoscopy: what should we tell the patient? A consensus statement of the European Laryngological Society.

INTRODUCTION: Informed consent for any surgical intervention is necessary, as only well-informed patients can actively participate in the decision-making process about their care, and better understand the likely or potential outcomes of their treatment. No consensus exists on informed consent for suspension microlaryngoscopy (SML). MATERIALS AND METHODS: Informed consent procedures in nine countries on five continents were studied. RESULTS: Several risks can be discerned: risks of SML as procedure, anesthesiologic risks of SML, specific risks of phonosurgery, risks of inadequate glottic exposure or unexpected findings, risks of not treating. SML has recognized potential complications, that can be divided in temporary (minor) complications, and lasting (major) complications. CONCLUSION: SML is a safe procedure with low morbidity, and virtually no mortality. Eleven recommendations are provided.

Endoscopic Resection and Mucosal Reconstitution With Epidermal Grafting: A Pilot Study in Idiopathic Subglottic Stenosis.

OBJECTIVE: To describe technical aspects and surgical outcomes of endoscopic resection and mucosal reconstitution with epidermal grafting (ie, the Maddern procedure) in the treatment of idiopathic subglottic stenosis. STUDY DESIGN: Medical record abstraction. SETTING: Johns Hopkins Hospital. METHODS: Retrospective series of 9 adults with idiopathic subglottic stenosis who underwent the Maddern procedure by a single surgeon over a 5-year period. Prespecified outcomes included (1) perioperative outcomes (Clavien-Dindo grade 4/5 complications, need for staged tracheostomy, hospital length of stay), (2) postoperative outcomes (peak expiratory flow rate [PEFR], need for subsequent airway surgery, tracheostomy at follow-up), and (3) patient-reported quality-of-life outcomes (Clinical COPD Questionnaire, Voice Handicap Index-10, Eating Assessment Tool-10, and 12-Item Short Form Version 2). Wilcoxon matched-pairs signed rank test and Kaplan-Meier analysis were performed. RESULTS: There were no Clavien-Dindo grade 4/5 complications; 2 patients required unplanned staged tracheostomy; and the median length of stay was 3 days. Following endoscopic resection and stent removal, a median of 2 laser resurfacing procedures were required. Two patients developed recurrent stenosis requiring cricotracheal resection (CTR). There were significant improvements in PEFR, Clinical COPD Questionnaire, and Voice Handicap Index-10, without significant difference in Eating Assessment Tool-10. The 12-Item Short Form Version 2 approximated the population norm. Kaplan-Meier analysis demonstrated significant improvement in time to surgery after the final laser resurfacing. CONCLUSION: The Maddern procedure has a low complication rate and offers durable physiologic improvement in PEFR, limiting need for additional procedures. Risks included need for CTR salvage, temporary tracheostomy, phlegm accumulation, and laryngospasm. It is a surgical option for patients with short dilation intervals who prefer to avoid the risks of CTR.

Emergency presentation of iatrogenic airway stenosis following intubation in a patient with COVID-19 and its management.

A 59-year-old man presented to the emergency department with recent onset biphasic stridor, dyspnoea and increased work of breathing on the background of prolonged intubation for the novel COVID-19 2 months previously. Flexible laryngoscopy revealed bilateral vocal fold immobility with a soft tissue mass in the interarytenoid region. The patient's symptoms improved with oxygen therapy, nebulised epinephrine (5 mL; 1:10 000) and intravenous dexamethasone (3.3 mg). The following morning, the patient was taken to theatre, underwent suspension microlaryngoscopy and found to have bilateral fixation of the cricoarytenoid joints and a large granuloma in the interarytenoid area. He underwent cold steel resection of the granuloma and balloon dilatation between the arytenoids, with the hope of mobilising the joints. This failed and CO2 laser arytenoidectomy was performed on the left side. The stridor had resolved postoperatively, with normalisation of work of breathing and the patient was discharged home on the first postoperative day.

The surgical management of recurrent tracheal schwannoma.

A case of a primary tracheal schwannoma refractory to endoscopic treatment in a 54-year-old male is reported. Previous treatment was by endoscopic laser debulking. Computed tomography (CT) 2 months later demonstrated a recurrent tumour involving the anterior tracheal wall with intraluminal tracheal extension. Treatment was successful by limited tracheal resection with primary anastomosis performed 2 weeks following the scan. The histology confirmed a benign neurogenic tumour derived from Schwann cells and clear margins.

A classification system for airway compromise due to bilateral vocal fold mobility impairment.

We present a system for classification of bilateral vocal fold mobility impairment. Type 1 obstructions are caused by bilateral laryngeal denervation, most commonly due to bilateral recurrent laryngeal nerve palsy. Type 2 obstructions are caused by crico-arytenoid joint ankylosis. Type 3 obstructions are due to inter-arytenoid granulation tissue. Type 4 lesions are caused by mature inter-arytenoid scar tissue and type 5 lesions are complex or total laryngeal stenoses.

An estimation of the population incidence of adult unilateral vocal fold mobility impairment in England.

We estimate the population incidence of adult unilateral vocal fold mobility impairment at 5.13 per 100,000 per year.

Physiology-based minimum clinically important difference thresholds in adult laryngotracheal stenosis.

OBJECTIVES/HYPOTHESIS: Delivering evidence-based patient care is predicated on the availability of objective and validated outcome measures. We aimed to calculate physiology-based minimum clinically important difference (MCID) values for adult laryngotracheal stenosis (LTS). STUDY DESIGN: Prospective observational study. METHODS: Patient demographics, morbidities, and stenosis severity were assessed preoperatively. Flow-volume loops and Medical Research Council (MRC) dyspnea grades were measured in 21 males and 44 females before and 6 to 8 weeks after airway surgery, and before treating recurrent disease in 10 patients. Anchor and distribution-based methodologies were used to calculate MCIDs for treatment efficacy and disease recurrence respectively. RESULTS: The mean age at treatment was 46 ± 16 years. The most common etiology was idiopathic subglottic stenosis (38%). Most lesions (66%) obstructed >70% of the lumen. There were strong correlations between treatment-related changes in total peak flow (TPF) (ΔTPF) (peak expiratory flow + |peak inspiratory flow|) and the ratio of area under the flow-volume loop (AUC) to forced vital capacity (FVC) (ΔAUCTotal /FVC), and treatment-related changes in the MRC grade (ΔMRC) (r = -0.76 and r = -0.82, respectively). Both TPF and AUCTotal /FVC discriminated between effective (ΔMRC <0) and ineffective (ΔMRC ≥0) interventions, yielding MCID values of 4.2 L/s for TPF and 2.1 L(2) /s for AUCTotal /FVC, respectively. Ten patients required airway treatment for recurrent disease, and TPF and AUCTotal /FVC levels had distribution-based MCID values of 0.9 and 0.6, respectively. CONCLUSIONS: Flow-volume loops provide a quantitative method of objectively assessing outcomes in LTS. TPF is the most convenient index for this purpose, but AUCTotal /FVC provides marginally greater sensitivity and specificity.

Management and prognosis of primary tracheal cancer: a national analysis.

OBJECTIVES/HYPOTHESIS: To perform a national review of the incidence and treatment of primary tracheal cancer and to identify gaps in service provision and factors associated with survival. STUDY DESIGN: Retrospective analysis of Hospital Episode Statistics data for England between 1996 and 2011. METHODS: Information about age, sex, morbidity, provider trust, diagnostic delay, nature of hospital admission and treatment, and palliation-free survival were recorded. The relationship between variables and survival was explored with Cox regression. RESULTS: There were 874 patients, giving an incidence of 0.9 per million. Mean age at diagnosis was 66 ± 13, and there were 456 (52%) males. Mean presentation to diagnosis latency was 2.5 ± 8 months, and 40% of patients presented as emergency admissions. There were 19 cases of oesophageal involvement and 241 cases of bronchopulmonary involvement; and 188 patients developed distant metastases. There were 60 curative resections (6.9%), which was the most significant predictor of palliation-free survival (hazard ratio: 0.23; 95% confidence interval 0.13-0.38). Other prognostic variables included age, sex, emergency admission, interventional bronchoscopy, chemotherapy, oesophageal involvement, and distant metastases. Ten-year palliation-free survival was 60.8% with curative resection and 19.5% overall. Eighty-six percent of patients were treated in units that treated fewer than one patient per year. CONCLUSION: Tracheal cancer is under-recognized and under-treated. Early diagnosis, access to interventional bronchoscopy, and surgical treatment in specialist units may improve the survival of patients with this condition.

Not always asthma: clinical and legal consequences of delayed diagnosis of laryngotracheal stenosis.

Laryngotracheal stenosis (LTS) is a rare condition that occurs most commonly as a result of instrumentation of the airway but may also occur as a result of inflammatory conditions or idiopathically. Here, we present the case of a patient who developed LTS as a complication of granulomatosis with polyangiitis (GPA), which was misdiagnosed as asthma for 6 years. After an admission with respiratory symptoms that worsened to the extent that she required intubation, a previously well 14-year-old girl was diagnosed with GPA. Following immunosuppressive therapy, she made a good recovery and was discharged after 22 days. Over subsequent years, she developed dyspnoea and "wheeze" and a diagnosis of asthma was made. When she became pregnant, she was admitted to hospital with worsening respiratory symptoms, whereupon her "wheeze" was correctly identified as "stridor," and subsequent investigations revealed a significant subglottic stenosis. The delay in diagnosis precluded the use of minimally invasive therapies, with the result that intermittent laser resection and open laryngotracheal reconstructive surgery were the only available treatment options. There were numerous points at which the correct diagnosis might have been made, either by proper interpretation of flow-volume loops or by calculation of the Empey or Expiratory Disproportion Indices from spirometry data.

Use of pressure-volume loops for physiological assessment of adult laryngotracheal stenosis.

OBJECTIVES/HYPOTHESIS: To assess the utility of intraoperative pressure-volume curves as an objective method of physiological disease stratification and outcomes assessment in adult laryngotracheal stenosis. STUDY DESIGN: Prospective observational study. METHODS: We prospectively studied 42 tracheotomy-free patients undergoing endoscopic laryngotracheoplasty over 18 months. Patient and lesion characteristics were obtained. Dyspnea severity was assessed using the Medical Research Council scale. Preoperative spirometry and intraoperative pulmonary compliance were recorded. RESULTS: There were 19 male and 23 female patients, and the mean age at treatment was 44 ± 16 years. There were 14 Myer-Cotton 1 lesions and 14 and 13 patients had grade 2 or 3 stenoses, respectively. Pulmonary compliance was strongly correlated with anatomical stenosis severity (r = 0.8, P < .0001) and perceptual dyspnea severity (r = 0.73, P < .0001). The strengths of correlation between pulmonary compliance and anatomical stenosis severity was significantly greater than those between forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and peak expiratory flow. The strength of correlation between pulmonary compliance and perceptual dyspnea severity was significantly greater than those between FEV1 and FVC with perceptual dyspnea severity. The two independent determinants of pulmonary compliance were Myer-Cotton stenosis severity (P < .0001) and patient age (P = .013). CONCLUSIONS: Pulmonary compliance provides an objective measure of physiological airway impairment. It correlates well with anatomical disease severity and perceptual dyspnea severity. Its more widespread use in adult patients and research into its utility in pediatric airway stenosis is recommended.

The larynx in cough.

About 40% of the population will experience chronic cough at some point during their lives and it tends to be more common in women (Thorax 58:901-7, 2003). Post-nasal drip (or upper airway cough syndrome), gastro-esophageal reflux disease and asthma are considered the most common causes. Yet only a small percentage of patients with these common conditions experience chronic cough. Also there is no agreed measure of post-nasal drip and controversy exists about the diagnosis of reflux above the upper esophageal sphincter (laryngopharyngeal reflux) based on observable changes to the larynx. The approach of the otolaryngologist is to consider the upper and lower airways as a continuum and that a common pathology can have an impact on all these anatomical sites.A multidisciplinary approach is advocated, utilising the skills of the respiratory physician, otolaryngologist, gastroenterologist and speech pathologist.

Diagnosis of laryngotracheal stenosis from routine pulmonary physiology using the expiratory disproportion index.

OBJECTIVE/HYPOTHESIS: The study's objective was to determine the utility of expiratory disproportion index (EDI), the ratio of forced expiratory volume in 1 second (FEV1) to peak expiratory flow rate (PEFR) (EDI = FEV1[L] /PEFR[L/s] × 100), in differentiating between laryngotracheal stenosis (LTS) and other respiratory diagnoses. LTS is an uncommon complication of mechanical ventilation or vasculitis or a manifestation of airway compression or malignancy. It frequently masquerades as asthma and evades timely diagnosis, causing prolonged morbidity and airway-related mortality. STUDY DESIGN: Observational study. METHODS: We compared spirometry results of 9,357 healthy subjects and nonstenosis pulmonary patients with 217 cases of LTS. Bootstrap analysis, receiver-operating characteristic (ROC) statistics, and Pearson correlation were used to assess the diagnostic utility of the EDI and its correlation with stenosis severity. RESULTS: Mean EDI values were 36 ± 7 in nonstenosis cases, 76 ± 17 in benign stenoses, and 69 ± 23 in tracheal cancer (P < .0001). A significant correlation existed between anatomic stenosis severity and EDI (P < .0001; R = 0.61). Area under the ROC curve was 0.98, and at a threshold of >50, EDI had a sensitivity of 95.9% and a specificity of 94.2% in differentiating between stenosis and nonstenosis cases. CONCLUSIONS: EDI can reliably diagnose LTS using routine lung function data. Its simplicity and clinical utility, first recognized by Duncan Empey, are underpinned by a unique physiology whereby PEFR, being determined by total tracheobronchial tree resistance, falls disproportionately compared with FEV1 , which is determined within small intrathoracic airways. EDI provides valuable information about the presence and extent of LTS particularly in nonspecialist clinical settings and its routine inclusion within standard lung function reports could prevent the prolonged morbidity and mortality that currently result from missed and delayed diagnoses.

Outcome of endoscopic resection tracheoplasty for treating lambdoid tracheal stomal stenosis.

OBJECTIVES/HYPOTHESIS: To evaluate the efficacy of endoscopic resection tracheoplasty (ERT) for treating post-tracheotomy stomal stenosis caused by inward collapse of tracheal ring remnants. STUDY DESIGN: Prospective observational study. METHODS: Between 2007 and 2012, we treated 40 patients with "lambdoid" tracheal deformity with a two-staged minimally invasive procedure undertaken using suspension microtracheoscopy and high-frequency jet ventilation. The first procedure entailed CO2 laser photoablation of collapsed tracheal rings and dilatation. The second procedure, performed 6 to 8 weeks later, involved ablation of residual structural obstruction, removal of granulation tissue, and intralesional corticosteroid injection. Perioperative patient and lesion characteristics and results of treatment were assessed. RESULTS: There were 22 males and 18 females, and mean age at first treatment was 59 years. There were 17 cases of scarring at the postero-lateral tracheal groove (trachealis blunting), and 22 patients had age-adjusted Charlson comorbidity scores greater than 4. All patients without trachealis blunting were successfully managed endoscopically, with only one patient requiring one additional endoscopic treatment. Seven patients with trachealis blunting needed additional treatment, and four patients had tracheal resection (P = 0.013). All patients were decannulated, and 75% of patients achieved good dyspnea outcomes. Patients with low morbidities were significantly more likely to achieve good dyspnea outcomes (P < 0.027). There were no treatment-related worsenings of voice or swallowing. CONCLUSIONS: ERT is an effective minimally invasive treatment for intubation-related lambdoid tracheal stenosis. It achieves a successful outcome while avoiding the risks associated with open surgery. We recommend its more widespread use for treating patients with this condition.

Outcome of treating airway compromise due to bronchial stenosis with intralesional corticosteroids and cutting-balloon bronchoplasty.

OBJECTIVES: To determine the feasibility, safety, and efficacy of treating benign bronchial stenosis with laryngoscopy, jet ventilation, intralesional corticosteroids, and cutting-balloon bronchoplasty. STUDY DESIGN: Case series with planned data collection. SETTING: National airway unit. SUBJECTS AND METHODS: Ten adult patients with bronchial stenosis caused by Wegener's granulomatosis (n = 6), tuberculosis (n = 2), intubation (n = 1), and photodynamic therapy (n = 1) who underwent bronchoplasty using cutting-balloon dilation via suspension laryngoscopy in 2009. Information about patient demography, etiology, lesion characteristics, and details of the interventions were recorded. Patients underwent spirometry before surgery and at last follow-up. Chest infection rate in the 6 months before bronchoplasty and from bronchoplasty to the last follow-up was ascertained. RESULTS: There were 3 men and 7 women. Mean age at bronchoplasty was 46 ± 20 years. Length of stay was 1 day in all cases, and no treatment-related complications occurred. One patient required a second bronchoplasty at 55 days. Mean follow-up was 7 ± 2.3 months. Forced expiratory volume in 1 second increased from a prebronchoplasty mean of 1.6 ± 0.6 to 2.2 ± 0.5 at last follow-up (P < .0001; paired Student t test). Forced vital capacity rose from 2.7 ± 0.6 to 3.1 ± 0.6 (P = .02), and peak expiratory flow rate increased from 3.7 ± 0.8 to 5.0 ± 0.8 (P < .0001). Chest infection rate fell from an average of 0.7 ± 0.3 infections per month to 0.2 ± 0.2 (P < .003; paired Student t test). CONCLUSION: Cutting-balloon bronchoplasty via suspension laryngoscopy is an effective treatment for benign bronchial stenosis. It is safer than airway stenting and is less invasive than thoracotomy. The authors propose its use as first-line treatment for this condition.

Endoscopic airway management of laryngeal sarcoidosis.

OBJECTIVE: To report the results of treating laryngeal sarcoidosis with intralesional steroids and minimally invasive laser surgery. Sarcoidosis is a rare multisystem inflammatory disorder of unknown cause. Laryngeal involvement is extremely rare, and its optimal management remains controversial. DESIGN: Retrospective medical chart review. Settings Tertiary care center/national referral airway reconstruction center. PATIENTS: Ten consecutive patients treated for laryngeal sarcoidosis between 2004 and 2008. MAIN OUTCOME MEASURES: Demographic and clinical information including extralaryngeal manifestations obtained from patient records, laryngeal anatomic subsite manifestation of disease, intraoperative findings, and scores from the Medical Research Council (MRC) dyspnea outcome assessment instrument (which was administered preoperatively, at the first postoperative outpatient visit 4-6 weeks later, and at last follow-up). RESULTS: The patients included 9 women and 1 man, a total of 2.8% of the unit's adult surgical airway case mix (10 of 353). Mean (SD) age at presentation was 37 (17) years. All patients presented with dyspnea and dysphonia; 2 required emergency tracheostomy prior to treatment. Six patients presented with isolated laryngeal sarcoid. Supraglottis and arytenoids were affected in all patients. The median number of endoscopic treatments was 2 (range, 1-4). Significant improvement in MRC dyspnea grading was found postoperatively (P < .05), and patients with tracheostomy were successfully decannulated. The mean (SD) follow-up time was 24 (18) months. There were no adverse effects of surgery. Nine patients had a substantial dose reduction or discontinuation of their systemic corticosteroid therapy following endoscopic treatment. CONCLUSIONS: Minimally invasive endoscopic surgery with intralesional corticosteroid injection and laser reduction is an effective method of controlling laryngeal sarcoid. It improves symptoms immediately with minimal morbidity and, most importantly, reduces the need for systemic steroid administration in most patients. This study supports early recognition and endoscopic intervention in the management of laryngeal sarcoidosis.

Role of planned postchemoradiotherapy selective neck dissection in the multimodality management of head and neck cancer.

OBJECTIVE/HYPOTHESIS: To assess the oncologic efficacy and functional outcome of selective postchemoradiotherapy neck dissection for stage IV head and neck squamous cell carcinoma. METHODS: Retrospective review of patients with N2-3 cervical metastases at presentation who underwent planned neck dissection after complete biopsy-proven clearance of primary site mucosal disease with chemoradiotherapy between 2000 and 2006. RESULTS: There were 31 males and 10 females. The average age at presentation was 57 +/- 9 years. The oropharynx was the most common primary site (n = 23; 56%). Forty-nine hemineck dissections were performed, including six bilateral and two revision procedures. Sixteen (39%) patients had residual viable postchemoradiotherapy neck disease. Patient weight did not deteriorate after neck dissection (P > .4). Two patients had persistently worsened postoperative swallowing. Ten patients required shoulder physiotherapy, of whom eight were treated with conservative measures. Five-year hemineck disease control and disease-specific survival rates were 92% and 64%, respectively. Presence of viable postchemoradiotherapy neck disease was the only independent predictor of regional control (P < .001; hazard ratio 0.00; 0.00-0.40) and disease-specific survival (P < .02; hazard ratio 0.23; 0.04-0.55). Surgery was twice more likely to confer therapeutic benefit than to cause a significant, albeit in most cases, transitory, complication. CONCLUSIONS: Neck dissection is a safe and effective procedure and a necessary component of the multimodality management of all head and neck cancer patients with N2-3 disease. It should be performed soon after satisfactory demonstration of primary site disease clearance. Universal deployment of radical surgery appears unnecessary and should, when possible, be abandoned in favor of more selective procedures to lessen morbidity.

Incidence and significance of myocardial injury after surgical treatment of head and neck cancer.

OBJECTIVE/HYPOTHESIS: To review the incidence of, and risk factors for myocardial injury after head and neck surgery to help optimize patient care and develop perioperative cardioprotective strategies. STUDY DESIGN: Observational cohort study. METHODS: Records of 65 patients surgically treated for upper aerodigestive tract squamous cell carcinoma between 2005 and 2006 were reviewed. Information about cardiovascular history, tumor characteristics, details of surgery, and postoperative complications were recorded. Patients had troponin assays on the third postoperative day. Logistic regression was used to identify risk factors for postoperative myocardial injury. RESULTS: The average age at presentation was 62+/-12 years. There were 46 (71%) males and 19 (29%) females. Troponin-positive and -negative groups were matched for age, sex, cardiovascular risks, comorbidity, site, tumor-node-metastasis status, and duration of the operations. Sixteen (25%) patients had postoperative myocardial injury including five clinical myocardial infarctions. Factors identified as independent predictors of postoperative myocardial injury were blood pressure level (odds ratio [OR] 1.17; 95% confidence interval [CI] 1.04-1.31; P<.02), intraoperative heart rate variability (OR 1.33; 95% CI 1.04-1.71; P<.02), and the degree of postoperative inflammatory response (OR 1.07; 95% CI 1.02-1.13; P<.001). CONCLUSIONS: Postoperative myocardial injury is a known independent predictor of cardiovascular prognosis. Its incidence in head and neck patients could potentially be reduced through stringent blood pressure management, tight intraoperative heart rate control, and dampening of the postoperative inflammatory response. Troponin testing is a valuable screening tool, and patients who have elevated levels postoperatively should be closely monitored and referred to a cardiologist for optimization of cardiovascular care.

Outcome of endoscopic treatment of adult postintubation tracheal stenosis.

OBJECTIVES/HYPOTHESIS: To assess the results of primary endoscopic treatment of adult postintubation tracheal stenosis, to identify predictors of a successful outcome, and better define the scope and limitations of minimally-invasive surgery for this condition. METHODS: Sixty-two consecutive patients treated between April 2003 and 2006 with initial endoscopic surgery were prospectively studied. Patient and lesion characteristics, treatment details, complications, decannulation, and open surgery rates were recorded. Actuarial analysis and Cox regression were used to identify predictors of decannulation and freedom from external surgery. RESULTS: There were 34 male patients and the average age was 45 +/- 16 years. The average stenosis height was 18 mm (range: 5-55 mm), and 82% of lesions were Myer-Cotton grades III or IV. Lesion height and intubation-to-treatment latency independently predicted success of endoscopic surgery. Ninety-six percent of patients with lesions <30 mm in height were treated endoscopically, but the success rate fell to 20% for lesions longer than 30 mm. Patients with recalcitrant lesions underwent airway augmentation (n = 11) or resection (n = 3), with a 79% success rate. All patients were decannulated, but some, predominantly morbidly obese patients, required long-term stents for dynamic airway compromise. Ninety-eight percent of re-interventions occurred within 6 months. CONCLUSIONS: Minimally invasive treatment is effective in postintubation airway stenosis and obviates the need for open cervicomediastinal surgery in most patients. Patients with old and long lesions are less likely to be cured endoscopically. For most patients in this subgroup, endoscopic surgery makes airway augmentation a viable, less invasive alternative to resection. Patients were unlikely to require further therapy after 6 months of symptom-free follow-up.

Quantifying the physiology of laryngotracheal stenosis: changes in pulmonary dynamics in response to graded extrathoracic resistive loading.

OBJECTIVES/HYPOTHESIS: A model of airway obstruction was developed to study the impact of changes in airway resistance on ventilatory mechanics. This was used to derive quantitative indices of airway obstruction to aid in the objective diagnosis and physiological monitoring of adult patients with laryngotracheal stenosis (LTS). METHODS: Six airway resistors, the characteristics of which mirrored the selective impediment to inspiratory airflow that occurs in patients with LTS, were created and calibrated. Maximum-effort flow-volume loops were obtained from 15 volunteers with resistors placed in series with the spirometer. Diagnostic and monitoring performances of various flow-volume indices were assessed with receiver-operating characteristics (ROC) and analysis of variance (ANOVA), respectively. Promising indices were further evaluated in patients with LTS. RESULTS: Experimentally, the ratio of expiratory and inspiratory flows at midvital capacity (MEF50/MIF50) and peak expiratory to inspiratory flow ratio (PEF/PIF) had diagnostic sensitivities of 87% and 89%, respectively. The best index, both experimentally and clinically, was the ratio of area under the expiratory and inspiratory curves (ratio of integrals), with experimental and clinical sensitivities of 97% and 100%, respectively. A clinical specificity of 95%, and area under the curve of 0.965 were achieved for this index. Both PEF/PIF and the ratio of integrals could identify step changes in airway resistance greater than 10 cmH2O . sec . L (P < .05; ANOVA). CONCLUSIONS: Flow-volume testing is simple and noninvasive and can be used to quantify the diagnosis and physiological monitoring of patients with LTS. The ratio of areas under the expiratory and inspiratory curves appears to be the optimal index for this purpose.